Comparison of Intraocular Pressure before and after Laser In Situ Keratomileusis Refractive Surgery Measured with Perkins Tonometry, Noncontact Tonometry, and Transpalpebral Tonometry

Cacho, Isabel; Sanchez-Naves, Juan; Batres, Laura; Pintor, Jesús; Carracedo, Gonzalo

doi:10.1155/2015/683895

Cited by 22 publications

(15 citation statements)

References 31 publications

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“…Moreover, CCT remained stable at 3 months and corneal curvature kept changing. Although some studies showed that the corneal curvature and CCT were related to IOP reduction, 15,28 Liu and Roberts 29 reported that differences in corneal biomechanics between individuals may contribute more than corneal thickness or curvature to IOP measurement errors, which was consistent with this study. After surgery, patients needed routine application of 0.1% FML to prevent inflammation and refractive regression for 2 months.…”

Section: Discussionsupporting

confidence: 89%

Intraocular Pressure Changes and Relationship With Corneal Biomechanics After SMILE and FS-LASIK

Wang

Dou

et al. 2016

Invest. Ophthalmol. Vis. Sci.

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Citation: Li H, Wang Y, Dou R, et al. Intraocular pressure changes and relationship with corneal biomechanics after SMILE and FS-LASIK. Invest Ophthalmol Vis Sci. 2016;57:4180-4186. DOI:10.1167/iovs.16-19615 PURPOSE. The purpose of this article was to evaluate intraocular pressure (IOP) changes and investigate the relationship with corneal biomechanics after small-incision lenticule extraction (SMILE) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK). METHODS.A total of 193 eyes of 193 patients who underwent SMILE and FS-LASIK procedures were included in this retrospective study. Data were collected preoperatively and postoperatively, including Goldmann-correlated IOP (IOPg), corneal-compensated IOP (IOPcc), corneal hysteresis (CH), and corneal resistance factor (CRF) by ocular response analyzer, noncontact intraocular pressure (IOP NCT ) by noncontact tonometer, and Ehlers, Shah, Dresden, Kohlhaas, Orssengo/Pye by the Pentacam corrected system. Changes in both groups and differences between groups were evaluated. Multiple linear regression models were constructed to explore factors influencing IOP changes.RESULTS. In SMILE, the IOPg, IOPcc, IOP NCT , and Kohlhaas decreased significantly at 1 month postoperatively (P < 0.01), whereas with the Ehlers formula they significantly increased (P < 0.01). IOPs decreased at 3 and 6 months compared with all preoperative values except Ehlers values (P < 0.01), but there was no significant difference between 3 and 6 months (P > 0.05). In FS-LASIK, the IOPg, IOPcc, and IOP NCT decreased significantly at 1 month (P < 0.01), whereas in the Ehlers and Shah formulas they significantly increased (P < 0.01). Compared with preoperative values, the IOPs decreased at 3 and 6 months except in the Ehlers and Shah formulas (P < 0.01). Only IOPg and IOPcc differed between 3 and 6 months (P < 0.05). The Ehlers and Shah formulas were closer to the preoperative IOP for both groups, with variation approximately 1 mm Hg at 6 months postoperatively. Preoperative IOP, postoperative corneal resistance factor, corneal hysteresis, and flat keratometry were enrolled into the regression equations.CONCLUSIONS. IOP underestimation after SMILE or FS-LASIK was related to corneal biomechanics as well as preoperative IOP and flat keratometry. IOP after SMILE seem to remain more stable. Accordingly, the Ehlers and Shah formulas were closer to the preoperative IOP. It may be useful to estimate future IOP with the best-fit models after surgery.

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Section: Discussionsupporting

confidence: 89%

Intraocular Pressure Changes and Relationship With Corneal Biomechanics After SMILE and FS-LASIK

Wang

Dou

et al. 2016

Invest. Ophthalmol. Vis. Sci.

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“…The unsatisfactory results of these approaches may be attributed to changes in biomechanics, which are considered basic parameters for these devices. [13][14][15][16][17][18][19][20] Because of the inaccuracy of GAT measurements following LASIK, there is an argument for the development of a correction formula to address this issue. The development of a correction formula has been suggested by several authors previously, but none of the proposals has so far gained wide acceptance or been considered suitable for application.…”

Section: Discussionmentioning

confidence: 99%

<p>Intraocular Pressure Calculation in Myopic Patients After Laser-Assisted In Situ Keratomileusis</p>

Helmy¹,

Hashem²

2020

OPTH

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Background: Corneal refractive surgery is widely used worldwide. Myopia is the most common reason for laser-assisted corneal refractive surgery (LASIK) and one of the risk factors for glaucoma. Intraocular pressure (IOP) measurement becomes variable postoperatively as the results are affected by the decrease in corneal thickness and biomechanics. This prospective clinical case study attempted to establish a simple correction formula for the calculation of IOP in post-LASIK myopic patients. Methods: This study included 300 eyes of 150 patients with myopia and myopic astigmatism as a refractive error who underwent LASIK. IOP was measured preoperatively and 6 months postoperatively. Preoperative and postoperative corneal thickness as well as ablation depth were measured. Statistical analysis was performed to detect the relationship between ablation depth and change in IOP. An attempt was made to construct a correction formula for the calculation of post-LASIK IOP. Results: The age of the patients ranged between 18 and 50 (mean ± SD 34.78±8.8) years. The spherical equivalent of refractive error ranged between −1.5 and −10 diopters. The mean IOP decreased significantly from 15.72±2.37 mmHg preoperatively to 11.71±2.24 mmHg postoperatively, with a mean difference of 4±1.75 mmHg (p˂0.001). A positive correlation was detected between corneal thickness and IOP difference among patients both preoperatively and postoperatively (p˂0.001). A positive correlation was identified between ablation depth and IOP change (p˂0.001). The correction formula for IOP was established: Real IOP=4+0.7(preoperative IOP)−0.3(ablation depth). Conclusion: IOP measurements change after corneal refractive surgery with LASIK. A corrected formula may be a good option for the proper calculation of post-LASIK IOP.

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“…IOP values before scleral CL wear were assessed by both GAT (Haag-Streit AT900, USA) and DT (BICOM Inc, Long Beach, NY, USA), to have comparable measurements before and after the contact lenses wear. 13 …”

Section: Methodsmentioning

confidence: 99%

Effects of Scleral Contact Lenses for Keratoconus Management on Visual Quality and Intraocular Pressure

Formisano

Franzone

Alisi

et al. 2021

TCRM

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To evaluate the visual acuity level achieved by scleral contact lens (CL) fitting in patients affected by keratoconus and to evaluate possible intraocular pressure (IOP) changes during the scleral CL wear using a transpalpebral tonometer. Methods: In a prospective case series a comparison was made between visual acuity obtained with glasses, RGP and 16.8mm diameter scleral CL in 30 consecutive patients affected by keratoconus. IOP was tested during scleral CL wear by transpalpebral Diaton Tonometer (DT) and also by Goldmann Applanation Tonometer (GAT) before and after scleral CL wear. Results: The mean logMAR visual acuity improved from 0.2±0.25SD with glasses and 0.1 ±0.02SD with RGP, to −0.002±0.041SD when using the scleral CL (p<0.05). The mean IOP value before scleral CL wear was 12.93mmHg±2.20SD when measured with GAT and 7.85mmHg±2.27SD when measured with DT. During scleral CL wear, IOP was assessed through DT, with a mean value of 8.86mmHg±2.36SD; values were stable after 8 hours of scleral CL use. Immediately after scleral CL removal, the mean IOP measured with GAT was 12.85mmHg ±2.40SD and the mean IOP measured with DT was 7.66mmHg±1.88SD. Therefore, during scleral CL wear, it was evidenced a small but statistically significant increase of the mean IOP value (1.01mmHg; p<0.01), with a reversion to values prior to application when scleral CL was removed. Conclusion: Scleral CLs remarkably improved visual acuity in keratoconus patients when compared to glasses or RGP contact lenses. Even if it was evidenced a small increase of the mean IOP value during their wear, it may not be significant in otherwise healthy eyes. Statistical analysis demonstrated good agreement between GAT and DT but their numerical values presented a constant gap, that should be taken into account when there is a need to relate the DT values to the reference ones.

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Comparison of Intraocular Pressure before and after Laser In Situ Keratomileusis Refractive Surgery Measured with Perkins Tonometry, Noncontact Tonometry, and Transpalpebral Tonometry

Cited by 22 publications

References 31 publications

Intraocular Pressure Changes and Relationship With Corneal Biomechanics After SMILE and FS-LASIK

Intraocular Pressure Changes and Relationship With Corneal Biomechanics After SMILE and FS-LASIK

<p>Intraocular Pressure Calculation in Myopic Patients After Laser-Assisted In Situ Keratomileusis</p>

Effects of Scleral Contact Lenses for Keratoconus Management on Visual Quality and Intraocular Pressure

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